Suction cleaners, as daily-use articles, are widely used for cleaning of indoors and outdoors. Conventional suction cleaners may be classified, by shape, into a horizontal suction cleaner, a vertical suction cleaner and a portable suction cleaner, and so on. The horizontal suction cleaner includes a fan which is used for generating vacuum and connected to a ground brush through components such as a hose and a long connecting tube, and etc. In cleaning, a main device is placed on the ground and can be dragged to move, and the hose is handheld by a person to clean the ground. However, such a suction cleaner has a large volume and a lot of components and is complicated to operate. Moreover, the fan is connected to the ground brush through the hose, which results in a long connection distance and a large energy loss. In the vertical suction cleaner, the ground brush is made integrally with a machine head. In use, the cleaning of the ground may just be performed by simply pushing the whole machine. This kind of suction cleaner is applicable for a large area of cleaning, and mainly facilitates the cleaning of the ground, however, it is very inconvenient for cleaning of a wall surface, a sofa, a window, a desktop and an electrical appliance, and so on. In order to make up for the above defects, a bypass hose is generally added to the machine head for connection to a variety of common hairbrushes and suction ports. This type of suction cleaner has a large volume, a high cost and is inconvenient for dust suction.
Chinese Patent CN 201110369036.3, announced on Apr. 30, 2014, discloses a vertical suction cleaner, which includes a chassis, a body, a dust collecting mechanism and a motor. The dust collecting mechanism is arranged on the body and includes a fan, a filter and a dust cup, and the dust cup is arranged on an upper end face of a main body of a fan seat. This vertical suction cleaner has a large dust collection capacity, but cannot be used in a separated mode, which causes a cleaning operation to be inconvenient.
A portable suction cleaner, for example a rod handheld separated-type suction cleaner, may be considered as a combination of a vertical suction cleaner and a handheld suction cleaner. The portable suction cleaner is more flexible in usage than the vertical suction cleaner and is used in a wider range than the handheld suction cleaner. With reference to FIG. 1, this type of suction cleaner mainly includes a ground brush, a push rod and a main device. The ground brush and the main device are connected to a front end and a back end of the push rod respectively, and the main device is detachable for being used independently as a hand-held suction cleaner, which facilitates cleaning of articles such as a wall surface, a sofa, a windowsill, a desktop and an electrical appliance. When cleaning the ground, the main device, the ground brush and the push rod may be combined to form a ground mopping suction cleaner. However, due to limitation of the space of a machine body, this kind of suction cleaner has a small main device for being portable, which causes the suction cleaner to have a small dust collecting device and a low dust collection capacity, and such a suction cleaner is not practical in a dusty place. Moreover, only one dust collecting device is provided in the handheld suction cleaner, thus, large particles of dust entering into the dust collecting device is prone to cause blockage. In addition, since only one dust collecting device is provided, it has to make the main device large in volume and large in weight, which causes inconvenience in taking and using.
Therefore, there is a demand for a separable and convenient suction cleaner that not only has an increased dust collection capacity and an additional primary filtration to prevent blockage, but also addresses issues such as the main device having a large weight and a large volume.